In conventional mobile network services, Human To Human (H2H) communication occupies the main position. In the H2H communication, since two participating parties are the human being having behavior control capability, a session actually is controlled by the behavior of the human being. With the development of mobile network services and automation control technology, at present, a new mobile communication mode, i.e. Machine To Machine (M2M) communication, appears, in which two parties of the communication are machine equipment.
A narrow definition of the M2M is the communication from machine to machine, however, broadly speaking, the M2M includes networking applications and services with intelligent interaction of machine terminals as the core. The M2M can provide, based on an intelligent machine terminal, an information solution for a client with multiple communication modes as access means, so as to meet the information requirement of the client on monitoring, commanding and dispatching, data collection and measurement and so on. The M2M can be applied to industry applications (for example, traffic monitoring, alarm system, sea rescue, vending machine, driving payment and so on), home applications (for example, automatic meter reading, temperature control and so on) and personal applications (for example, life detection, remote diagnosis and so on) and the like.
Different from the H2H communication, the communication objects of the M2M are machines, and the communication behavior is automatically controlled, that is to say, initiation and termination of the communication and control of some admissions and limits during the communication procedure are automated behaviors. These behaviors depend on the restriction and control on the behavior of machines in the M2M communication (that is, terminals in the M2M communication), wherein the behavior of the terminals in the M2M communication are restricted by service subscription data and the network manages the terminals in the M2M communication according to the service subscription data.
The M2M communication also is called MTC, and the most typical example thereof is the communication between a terminal and an application server, wherein the terminal is called an MTC User Equipment (MTC UE) and the application server is called an MTC Server.
In the access of 2G/3G/Long Term Evolution (LTE), the M2M communication mainly takes a Packet Service (PS) network as an underlying bearer network to realize the service layer communication between the MTC UE and the MTC Server. FIG. 1 shows an architecture schematic diagram of the access of M2M communication entities to an Evolved Packet System (EPS).
In FIG. 1, the underlying bearer network comprises: an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), a Mobility Management Entity (MME), a Serving GateWay (S-GW or SGW), a Packet Data Network GateWay (PDN GW or P-GW or PGW), a Home Subscriber Server (HSS) and a Policy and Charging Rules Function (PCRF), wherein the main network element of the E-UTRAN is Evolved NodeB (eNodeB).
In FIG. 1, the MME takes charge of the related work of control plane, such as mobility management, process of non-access layer signaling and context management in user mobility management; the S-GW is an access gateway device which is connected to the E-UTRAN, and is configured to forward data between the E-UTRAN and the P-GW and take charge of the caching of paging waiting data; the P-GW is a border gateway between the EPS and Packet Data Network (PDN) and takes charge of functions such as the access of the PDN and the data forwarding between the EPS and the PDN and so on; the PCRF is a policy and charging rules function entity which is connected with an operator Internet Protocol (IP) service network through a receiving interface Rx to acquire service information, in addition, the PCRF can be coupled with a gateway device in the network through a Gx interface to take charge of initiating establishment of IP bearer, guarantee the Quality of Service (QoS) of service data and perform charging control; and the HSS provides management of user subscription data and management of important context information about access of the user to a network.
In FIG. 1, the MTC UE accesses the EPS network through the E-UTRAN (eNodeB); after an IP address is allocated, an IP channel can be established between the MTC UE and the MTC Server to realize an upper layer service communication between the MTC UE and the MTC Server. The IP channel established between the MTC UE and the MTC Server is a logic IP channel, the physical path of which passes through the eNodeB, the S-GW and the P-GW.
At present, a method to realize the M2M communication is to establish a service layer interface protocol on the IP channel between the MTC UE and the MTC Server, through the service layer interface protocol, service data are interacted between the MTC UE and the MTC Server, meanwhile, the MTC Server also realizes the control of the MTC UE through the service layer interface protocol.
FIG. 2 shows a flow of realizing the M2M communication by using the method above. As shown in FIG. 2, in the method, the procedure that an MTC UE accesses through a PS network and establishes communication connection with an MTC Server mainly comprises the following steps.
S201: the MTC UE initiates an Attach Request to an MME.
S202: the MME receives the Attach Request above and sends a Location Update Request to the HSS. In this step, the HSS downloads subscription data of the MTC UE to the MME, wherein the subscription data include the subscription data part used for M2M access control.
S203: the MME sends a bearer establishment request to an SGW/PGW to request the SGW/PGW to establish a proper bearer for the MTC UE.
S204: if the PGW needs to acquire policy data from a PCC to establish a proper bearer according to the policy data, the PGW interacts with the PCC to acquire the PCC policy.
S205: the PGW establishes a bearer for the MTC UE and returns a bearer establishment response.
S206: the MME sends an Attach Response to the MTC UE.
After step S206, the MTC UE attaches to the PS network and is allocated with an IP address and has a proper bearer established, thus the MTC UE is able to initiate registration of a service layer to the MTC Server.
S207: the MTC UE initiates registration of the service layer to the MTC Server.
S208: the MTC Server accepts the registration of the MTC UE and returns a registration response.
S209: service data interaction with the MTC Server is performed by the MTC UE through a service layer protocol.
Through the flow shown in FIG. 2, the MTC UE accesses the PS network and establishes an IP connection with the MTC Server, thus the MTC UE can realize the subsequent service layer communication with the MTC Server. In the flow, since the MTC Server has no relation with the underlying access layer (refer to the network elements such as MME/SGW/PGW), the MTC Server can not acquire events occurring in the underlying access layer, thus the MTC Server can not judge whether the behavior of the MTC UE is normal according to these events. Therefore, some M2M services requiring the service layer to have higher control right (for example, the M2M communication with high availability, the M2M communication with intelligent management capability, etc.) can not be realized by using the access method above.
For example, in some M2M communications with high availability, for the purpose of performing intelligent management and real-time monitoring to an MTC UE, the MTC Server requires to regularly check the condition of the MTC UE accessing the network to confirm that the operation of the MTC UE is normal and no failure occurs. In another aspect, if the behavior of the MTC UE accessing the network is abnormal, the MTC Server needs to learn the abnormal condition in time so as to notify the M2M operation and maintenance personnel to perform on-site maintenance in time. Or, in a condition that the equipment might be stolen, the MTC Server needs to have the capability of detecting the probable condition of equipment being stolen and system being misappropriated in time, so as to respond in time.
Particularly, in the M2M communication with higher demand on intelligent management and real-time monitoring, in order to meet higher management requirement, the MTC Server probably needs to acquire the condition of the MTC UE accessing the network in time; typically, the MTC Server probably needs to acquire the following information related to the MTC UE:
(A) regular access monitoring: for some services, it is required to limit the time when the MTC UE accesses the network, if the access to the network occurs at a forbidden time, the MTC Server needs to learn the condition in time;
(B) area access limit: for some services, it is required to limit the location area from which the MTC UE accesses the network, if the access to the network occurs at a forbidden location area, the MTC Server needs to learn the condition in time;
(C) mobility limit: for some services, the MTC UE is allowed to move in a preset area only, or the MTC UE is not allowed to move frequently, if the forbidden mobility behaviors above occur, the MTC Server needs to learn the condition in time;
(D) SIM misappropriation check: since the fee of the M2M communication probably is lower than that of general mobile communication, if the SIM card of the MTC UE is misappropriated, the service operator would suffer great loss; in order to prevent the occurrence of these conditions, the service operator probably requires to bind the International Mobile Subscriber Identification Number (IMSI) in the SIM card and International Mobile Equipment Identity (IMEI) of the MTC UE, that is, one IMSI can only be used by the MTC UE with one specified IMEI. In this condition, the MTC server needs to verify the binding of the IMSI and the IMEI of the MTC UE.
For the service requirements above, the related information of the MTC UE can only be acquired by the underlying access layer, in the E-UTRAN access, only the MME can acquire and judge necessary information. From the architecture of the present M2M communication (refer to the communication between the MTC UE and the MTC Server) accessing the EPS, the occurrence of the limit conditions above is generated in the access layer (for example, MME, PGW), and the service layer (for example, MTC Server) can not acquire the information. Also, for a location sensitive service, the service layer (for example, MTC Server) dose not know the information of the current exact location of the MTC UE and the occurrence of location event (cell handover), however, the information must be provided by the underlying access layer, therefore, in prior art, the MTC Server can not realize the real-time control and intelligent control of the MTC UE.
Besides, in some condition, the MTC Server might not be operated by an operator and the deployment point generally is not in a core network, thus, a threat would be caused to the security of the core network when the MTC Server acquires information from the core network side.